Lawn-mower grinder



R. H. MADSEN.

LAWN MOWER GRINDER.

APPLICATION FILED JULY 22, L920.

- Patented Noy. 29, 1921.

earner eerie.

LAWN-MOWER GRINDER.

messes.

Specification of Application filed July 22,

To all whom it may concern:

Be it known that l, RASMUS H. li l'AnsnN, a citizen of the UnitedStates, residing at Los .Angeles, in the county of Los Angeles and Stateof California, have invented new and useful Improvements in Lawn-MowerGrinders, of which the followingis a specification.

This invention is a lawn mower grinder forming improvements in theconstruction covered by-my Patent No. 1,291,982, granted January 21,1919 for lawn mower grinders.

It is the object of the present invention to provide means for adjustingthe guide plate engaging the rotary blades of the lawn mower so'thatblades of different widthmay be engaged by the guide plate.

It is a further object of the invention to provide means for adjustingsaid guide plate relative to the grinding wheel in order that the rotaryblades maybe properly positioned for obtaining the proper beveledcutting edge upon said blades.

It is a still further object of the invention to provide an improvedmounting for the guide plate supporting thestationary blade of the lawnmower, said mounting consisting of a main supporting screw for theentire guide plate and an auxiliary adjusting screw for adjusting themovable member of said guide plate.

The invention will be readily understood from the following descriptionof the accompanying drawings, in which Figure 1 is. a side elevation ofthe improved grinder and showinga portion of a lawn mower inverticalsection with a rotary blade thereof in position to be ground.

Fig. 2 is atop plan view of the improved grinder. d

Fig. 3 is a detail horizontal section on the line 3,3 of Fig. 1.

In the drawings I have shown a portion of a usual lawn mower having thewheels, 1, shaft 2 for the rotary blades 3, and fixed blade 4, all ofany usual or preferred construction.

- As in my aforementioned patent the grinder consistsessentially of amain bar 5, adapted to be supported at right angles to shaft 2, andcarrying a rotatable grinding wheel 6. This bar is provided with meansfor engaging either the fixed or one of the rotary blades of the mower,at the end of said bar 5 carrying the grinding wheel, so that said bladewill be held in engagement against the L er P n Patented'Nov. 29, 1921.

1920. Serial No. 398,158.

mentioned patent, for rotatingthe shaft 7' journaled along side bar 5,and at the same time shifting the apparatus transversely along thelength of the blades.

The grinding wheel 6 is j ournaled beyond 9. bearingplateS extendingbeyond the end of bar 5 at one sidethereof, and in a second bearingplate 10 extending beyond the opposite side of bar A bevel gearconnection 11.'12 is provided between shafts 9 and 7 for causingrotation of shaft 7 to turn the grinding wheel.

A supporting plate 14 extends beyond the grinding wheel and is,preferably, adjustably mounted relative to thesame. As an instance ofthis arrangement the supporting plate may be connected at one side tothe bearing plate 10 which is in turn adjustably connected to bar 5 bymeans of screw 15 received in slot 16 in said bearing plate. At theother side, the supporting plate is shown as connected to a plate 17which is adjust ably connected to bearing plate 8 as by the screw andslot connection 18-19. The hearing for shaft 9 formed in plate 10 is,preferably, an elongated hearing, so that the supporting plate, withplates 10 and 17 may be adjusted toward and away from thegrinding-wheel.

The guide plate for the stationary blade of the lawn mower depends fromsupporting'plate 14. This guide plate is shown as comprising a crosshead 21 having the upwardly extending guides 22 slidably received insleeves 23 upon supporting plate 14. An arm 24 extends downwardly fromthe side of the cross head adjacent wheel 6, and a finger 25 extendsbackwardly from the lower end of arm 24 to engage under the stationaryblade 4 of the lawn mower.

A plate 26 extends parallel to finger 25 and is adapted to impingeagainst the top of blade 4. The ends of'plate 26, preferably,- overliethe sides of arm 24 as shown at 27 in The bar is also provided .bar 5and in alinement therewith as by mount ng saidwheel upon a transverseshaft This shaft may be journaled in a fixed from the plate through athreaded sleeve 29 upon cross head 21, with a coil spring 30 interposedbetween said "cross llGtt plate.

The upper end of screw tends through supporting plate 1% and is providedwith a suitable thumb nut 32 for turning the same to adjust the distancebetween plate 26 and finger 25, so that blades oi varying thickness maybe held by the guide plate. j 7

hen the rotary blades of the lawn mower are being sharpened, the wheel 6is raised relative to the entire guide plate for the sta tionary blade,to the position shown in Fig. 1, for supporting the wheel 6 out ofengagement with the stationary blade. When, however, the stationaryblade is to be sharpened the wheel 6 is elevated relative to the guideplate to bring the grinding wheel into contact with said blade. j

The means employed for thus shifting the guide plate may consist of ascrew rod 34: extending upwardly from cross head 21.

through a split clamping screw threaded sleeve 85'upon supporting plate1 1'. The

clamping sleeve may be provided with a clamp screw 36 for tightening thesame and thus holding screw rod "and the guide plate in adjustedpositions.

A slot 38 is formed through the arm 24. so that the edge of the grinder6 will extend through the slot and grind the edge of the fixed blade 4as the grinder moveslaterally along the same. I

An adjustable guide plate a0 is arranged to engagethe respective rotaryblades 3; for

retaining the latter in position to be ground. This guide platelSPI'OVlClGd with a slot 41.

intermediate of its ends through which is received a screw 42 threadedinto the plate 17. The guide plate is thus arranged to be longitudinallyadjusted so as tomove the lower end thereof toward and away from thegrinding wheel 6 for positioning the rotary blade engaged thereby inadjusted positions relative to the grinder wheel. I

The lower end of the guide plate 40 consists of a fixed finger 43arranged to impinge against one side of a rotary blade 3 and a pivotedfinger 44 arranged to abut against the opposite side of the rotaryblade. The finger a l may be swung toward and away from finger 4&3 inorder to engage blades of varying thickness bymounting the fingerld upona pivot bolt 45 extending through the guide plate 4L0. A screw rod 46 isrotatably connected to the fixed finger l3 as by means of the bearingbraclrettr", and said screw rod is threaded through a bearing bracket 48upon the pivoted finger a l so that rotation of said screw rod bygrasping-thethumb nut 49 provided thereon will move the pivoted and th 228, preferably, ex-

1 rod 50 extendslaterally from the upper end oi guide plate d0 and isprovided with a thumb screw 51 held against longitudinal movementrelative to the screw rod between suitable brackets'52 mounted upon bar5 and positioned at the opposite faces oi the thumb nut. It will thus beseen that when screw 4-2 is loosened the guide plate d0 may beaccurately pivotally adjusted upon said screw by rotating the thumb nut51 so as to draw the screw rod 50 through said thumb nut.

Various changes may be made without de parting from the spirit of-theinvention as claimed. a

What is claimed is:

1. In a lawn mower grinder having a supporting frame secured to a lawnmower and a grinding wheel carried thereby, a guide 90 plate arranged toengage a blade'of the lawn mower, and an operating connection forpivotally and longitudinally adjusting said guide plate. p

2. In a lawn mower grinder having a supporting frame secured to a lawnmower and a grinding wheel carried thereby, a guide plate arranged toengage a blade of the lawn mower, said guide plate including a fixedfinger and a pivotally adjustable finger, said 100 fingers beingarranged to engage the respecarranged to engage the respective sides ofsaid blade, and an operating connection for pivotally andlongitudinally; adjusting said guide plate.

4. In a lawn mower grinder having a supporting frame secured to a lawnmower and a grinding wheel carried thereby, a guide plate arrangedtoengagea rotary blade of the lawn mower, means for adjustingflsaid guideplate relative to said grinding wheel, said guide plateincluding a fixedfinger ar-' ranged to engage the under side of a rotary 1'20 blade, andan adjustable plate movabletoward and away from saidfixed finger'forengaging the upper side of said rotary blade;

. 5. Ina lawn mower grinder'having a sup[- porting frame secured to alawn mower and a grinding wheel carried thereby, a guide plate arrangedto engage a rotary'blade of the. lawn mower, means for adjusting saidguide plate relative to said grinding wheel,

.said guide plate includinga fixed finger arranged to engage the underside of a rotary blade, an adjustable plate movable toward and away fromsaid fixed finger for engaging the upper side of said rotary blade, aguide plate arranged to engage the station ary blade of the lawn mower,and actuating means for pivotally adjusting said guide plate.

6. In a lawn mower grinder having a supporting frame secured to a lawnmower and a grinding wheel carried thereby, a guide plate arranged toengage a rotary blade of the lawn mower, means for adjusting said guideplate relative to said grinding wheel, said guide plate including afixed finger arran ed to engage the under side of a rotary blade, anadjustable plate movable toward and away from said fixed finger forengaging the upper side of said rotary blade, a guide plate arranged toengage the stationary blade of the lawn mower, said guide plateincluding a fixed finger and a pivotally adjustable finger arranged toengage the respective sides ofsaid stationary blade, and actuating meansfor pivotally adjusting said guide plate.

In testimony whereof I have signed my name to this specification.

RAbMUS H. MADSEN.

